I visited the Tower Bridge with my mom when she was here in May.
The bridge plays a big part of London's history, as I'm sure you can understand. Originally, the upper walkways were created so pedestrians could continue upon their journey instead of waiting for the bridge to open for river traffic. By the time 1910 arrived, the walkways were closed because it was more complicated to travel to the top. Today a quick elevator ride takes you to the top in a flash. The bridge continues to open several times per day to allow for larger boat traffic along the River Thames, and it is a beautiful sight.
Many sites in London were damaged or destroyed during the Blitz (1940-41). However, Tower Bridge was spared because the Germans used it as a geographic landmark. Pedestrians wait for the bridge to return to its horizontal resting place, and tourists spend time in the walkways above. The views down the River Thames provide a quiet, peaceful aspect of the city.
Tower Bridge Experience Adults £9 (buy online for £8). Opening hours are from 10am-6pm in the summer & 9:30am-5:30pm in the winter. Your best bet is to take the Circle Line or District Line to Tower Hill for an easy walk to the bridge.